Fair Value Measurements - Change in Redeemable Noncontrolling Interests (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Redeemable Noncontrolling Interests [Roll Forward]
Balance at beginning of period	$ 38,624	$ 28,885
Initial redeemable noncontrolling interest related to business combinations		9,409
Net income attributable to redeemable noncontrolling interests	1,278	1,371
Adjustment of the redeemable noncontrolling interests to fair value	1,756	2,349
Effect of foreign currency translation attributable to redeemable noncontrolling interests	(922)	(3,390)
Balance at end of period	$ 40,736	$ 38,624